BH: Boost C++ Header Files

Boost provides free peer-reviewed portable C++ source
libraries. A large part of Boost is provided as C++ template code
which is resolved entirely at compile-time without linking. This
package aims to provide the most useful subset of Boost libraries
for template use among CRAN package. By placing these libraries in
this package, we offer a more efficient distribution system for CRAN
as replication of this code in the sources of other packages is
avoided.